AU2020202521A1

AU2020202521A1 - Improvement in Joists

Info

Publication number: AU2020202521A1
Application number: AU2020202521A
Authority: AU
Inventors: Danny Strangio
Original assignee: Steel Building Systems Australia Pty Ltd
Current assignee: Steel Building Systems Australia Pty Ltd
Priority date: 2019-04-12
Filing date: 2020-04-14
Publication date: 2020-10-29

Abstract

The invention is a modification of a cold rolled light gauge steel floor joist to improve the process and ease of installation and in doing so, improving the safety of the installers and minimising the time spent working at height. The modification is to the top chord of the joist, and comprises an extension tab which is either integral to the top chord of the joist or is an added piece of steel, attached to the top chord, which extends past the end of the joist and allows the joist to be rested, by the tab, on the top plate of the perimeter beam. Figure 5 $- A A3 j Assembled view

Description

Figure 5

$- A

A3 j Assembled view

AUSTRALIA

Patents Act 1990

COMPLETE PATENT SPECIFICATION IMPROVEMENTS IN JOISTS

The invention is described in the following statement:

FIELD OF INVENTION

[001] The invention is a modification of a cold rolled light gauge steel floor joist to improve the process and ease of installation and in doing so, improving the safety of the installers and minimising the time spent working at height..

BACKGROUND TO THE INVENTION

[002] When installing the floor joists for the upper floors of a multi-storey building, the joists need to be installed before the rest of the upper floor can be built. This usually involves at least two workers lifting a joist to at least 2m above the ground, and holding it until it is attached by fastening means to the perimeter beam of the upper storey. A joist is a substantial building element which is heavy and long and unwieldy. The workers are often on ladders or temporary scaffolds, all of which creates significant risks of injury due to lifting and working at height. The secure attachment of the joist to the perimeter beam can take some time and involves the use of brackets and attachments such as rivets or bolts or screws. The present invention aims to limit the time that the joist is required to be handled by workers and aims to facilitate its placement within the building.

SUMMARY OF INVENTION

[003] It is an object of this invention to provide an improved steel floor joist, that allows the joist to held in place , whilst the joist is being attached to the perimeter beam, and the weight of the joist does not need to be supported by people working at height.

[004] In a first aspect of the invention is an improved steel floor joist, the improvement comprises a pair of extension tabs which are either integral to the top chord of the joist or are added pieces of steel, attached to the top chord, at the distal ends of the joist, which extend past both ends of the joist and allow the joist to be rested, by the tabs, on the top plate of the perimeter beam, whilst the joist is being attached to the perimeter beam by attachment means.

[005] In a second and preferred aspect of the invention is an improved steel floor joist, the improvement comprises a pair of extension tabs which are integral to the top chord of the joist, at distal ends of the joist, which extend past both ends of the joist and allow the joist to be rested, by the tabs, on the top plate of the perimeter beam, whilst the joist is being attached to the perimeter beam by attachment means.

[006] In a third aspect of the invention is a method of installing an improved steel floor joist in a building comprising:

1. Resting an improved floor joist on the perimeter beam of the building, using the improvement of a pair of extension tabs which are either integral to the top chord of the joist or are added pieces of steel, attached to the top chord, at distal ends of the joist, which extend past both ends of the joist, and allow the joist to be rested, on the top plate of the perimeter beam; and 2. Attaching the improved floor joist to the perimeter beam with an attachment means.

BRIEF DESCRIPTION OF THE DRAWINGS

[007] Figure 1 is an iso view of an upper floor joist, 1, comprising a top chord, 2, a bottom chord, 3, an end, 4, partial view of the some of the webs of the joist, 5 and 6, and the tab of the invention, 7.

[008] Figure 2 is a view from the top of the joist showing the top chord, 2, and the tab of the invention, 7.

[009] Figure 3 is a view from the bottom of the joist showing the bottom chord, 3, and the tab of the invention, 7.

[010] Figure 4 shows the upper floorjoist, 1, comprising a top chord, 2, a bottom chord, 3, an end, 4, partial view of the some of the webs of the joist, 5 and 6, and the tab of the invention, 7.

[011] Figure 5 shows the upper floor joist, 1, in position on a perimeter beam, 8, comprising a top plate, 9, bottom plate, 10 and an upright, 11.

DETAILED DESCRIPTION OF THE INVENTION

[012] The following detailed description of the invention refers to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts. Dimensions of certain parts shown in the drawings may have been modified and/or exaggerated for the purposes of clarity or illustration.

[013] In the present specification and claims (if any), the word "comprising" and its derivatives including "comprises" and "comprise" include each of the stated integers but does not exclude the inclusion of one or more further integers.

[014] In a first aspect of the invention is an improved steel floor joist, the improvement comprising a pair of extension tabs at distal ends of a top chord of the joist, which extend past both ends of the joist and allow the joist to be rested, by the extension tabs, on the top plate of a perimeter beam of a floor structure.

[015] In a second aspect of the invention is an improved steel floor joist, the improvement comprising a pair of extension tabs which are either integral to a top chord of the joist or are added pieces of steel, attached to the top chord, at the distal ends of the joist, which extend past both ends of the joist and allow the joist to be rested, by the tabs, on the top plate of a perimeter beam of a floor structure.

[016] In a third aspect of the invention is an improved steel floor joist of claims 1 and 2, the improvement comprising a pair of extension tabs which are integral to the top chord of the joist, at distal ends of the joist, which extend past both ends of the joist and allow the joist to be rested, by the tabs, on the top plate of a perimeter beam of a floor structure.

[017] In a first aspect of the invention is an improved floor joist, the improvement comprises a pair of extension tabs which are either integral to the top chord of the joist or are added pieces of steel, attached to the top chord, at distal ends of the joist, which extend past both ends of the joist and allow the joist to be rested, by the tabs, on the top plate of the perimeter beam, whilst the joist is being attached to the perimeter beam by attachment means.

[018] In a second and preferred aspect of the invention is an improved floor joist, the improvement comprises a pair of extension tabs which are integral to the top chord of the joist, at distal ends of the joist, which extend past both ends of the joist and allow the joist to be rested, by the tabs, on the top plate of the perimeter beam, whilst the joist is being attached to the perimeter beam by attachment means.

[019] In a third aspect of the invention is a method of installing an improved floor joist in a building comprising:

1. Resting an improved floor joist on the perimeter beam of the building, using the improvement of a pair of extension tabs which are either integral to the top chord of the joist or are added pieces of steel, attached to the top chord, at distal ends of the joist, which extend past both ends of the joist, and allow the joist to be rested, on the top plate of the perimeter beam; and

2. Attaching the improved floor joist to the perimeter beam with an attachment means.

[020] Whilst cold rolled steel is much lighter than structural steel, floor joist made out of a top chord, a bottom chord and end chords, being the outer chords, to form a rectangle, with a series of web members extending between the outer chords, in any kind of configuration, but usually an series of angled struts to form triangles with the outer chords, is still a heavy and unwieldy object. The chords and web members are traditionally made of C-shaped channels of cold rolled steel, and are joined together either by screws, rivets or welds or any other kind of suitable attachment means.

[021] When the joist are being installed, especially to form the floor of an upper storey of a building, the workers installing the joists usually have to work at height with the heavy, unwieldy joist above their heads, holding it in place until another worker, or pair of workers, can attach the joist to the perimeter beam that extends around the area, within which once the joists are installed, they will be the basis of a floor. The joist can be attached to the perimeter beam by any suitable attachments means including screws, bolts, rivets, welds, and may involved the further use of brackets, plates or strapping, all of which are well know in the art.

[022] Alternatively, a floor joist may be held in place by a crane or other mechanical lifting apparatus, which are expensive to hire.

[023] The are some brackets that are used which are attached to the perimeter beam and the joist is cradled within the bracket while further secure attachment is undertaken. However, these have drawbacks as the size of joists can varying depending the dimensions of the area to be spanned and the loads that the joist needs to carry. So they are not a universal solution, as they have to be fitted for each set of joists, at the appropriate predetermined height before the perimeter beam and the joists are delivered to site.

[024] The inventors wanted a solution that allowed for a solution to be attached or manufactured in the factory and that was a universal solution, i.e. that for each individual job the placement of the hanging brackets on the perimeter beam did not need to be calculated.

[025] The tabs on the end of the top chord of the improved floor joist of the invention allow the floor joist to be hung, or rested on the top plate of the perimeter beam, and then the appropriate brackets and attachment means can be installed on site, without predetermined calculations for placement.

[026] The floor joist of the invention will always result in the top of the joist be almost flush with the top of the perimeter beam, and will always allow for the correct placement of the attachment means, while at the same time reducing the time that people are working at height supporting heavy loads. The perimeter beam will carry the load of the joist while the attachment means are used to attach the joist to the perimeter beam, and the workers at height will only need to provide a steadying hand.

[027] The improved floor joist of the invention will also allow for changes to be easily made on site, in the case of unforeseen issues, or changes to the building during the building process.

[028] The tabs on the distal ends of the upper chord of the improved floor joist are not intended to be load bearing in the completed building. The attachment means used to attach the joist to the perimeter beam are intended to provide the strength of the joist as an upper flooring system.

[029] There are two possible options for forming the extension tabs: 1. The tabs are formed integral to the top chord during the cold rolling, and cutting process; or 2. The tabs are separate piece of steel attached to the top chord during the assembly of the joist.

[030] Either method has its advantages. The first method will be more expensive as tooling will need to be included in the processing of the steel that includes a cutting step to make the tab, but it would be hoped that the expensive of the tooling will soon be recovered in the speed of the process and not having to pay for the time of the assembler in attaching another piece of steel during the assembly of the joist. The second method is a simple method but adds another step to be included in the assembly of the joist and introduces a possible source of human error in forgetting to add the extension tab.

[031] Figure 1 shows one end of the improved floor joist, 1, of the invention. The top chord, 2, is attached to the end chord, 4, which is also attached to the bottom chord, 3, and the webs members, 5 & 6, are at least partially shown. The extension tab of the invention, 7, is shown at the end of the top chord.

[032] The amount that the extension tab extends past the end of the joist is not a set length, but a matter of practicality. It has to extend far enough to allow the joist to rest on the perimeter beam, but it should not extend so far that it interferes in the rest of the building process. There are also economics to be considered. The extension tab needs to be long enough to allow the resting of the beam, but not so long that it adds greatly to the expense of the joist.

[033] Figure 4 shows the improved floor joist of the invention, 1, resting on the perimeter beam 8. In this example it is shown as a beam made out of the same kind of C-channel material as the floor joist of the invention, but it may also be made out of structural steel, laminated wood beams, or any other suitable material for making perimeter beams.

[034] The extension tab, 7, can be seen extending from the end of the top chord, 2, and allowing the joist, 1, to rest on the perimeter beam, 8.

[035] The thickness of the light gauge steel used can be any suitable thickness and will again depend on the area to be covered and the load to be carried by the floor joists. The appropriate thickness of the steel is well known in the art.

[036] The shape of the tab needs to be fit for purpose. As such, a very narrow tab is unlikely to have the strength, even in the short time, to support the joist on the perimeter beam, so it is preferred to have a tab that is almost as wide as the width of the C-channel.

[037] The attachment means used to form the joist are well known in the art as are the attachment means for connecting the joist to the perimeter beam.

[038] Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus. Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in this field.

EDITORIAL NOTE 2020202521

There are only 1 page of claims

Claims

1. An improved steel floorjoist, the improvement comprising a pair of extension tabs at distal ends of a top chord of the joist, which extend past both ends of the joist and allow the joist to be rested, by the extension tabs, on the top plate of a perimeter beam of a floor structure.

2. An improved steel floorjoist, the improvement comprising a pair of extension tabs which are either integral to a top chord of the joist or are added pieces of steel, attached to the top chord, at the distal ends of the joist, which extend past both ends of the joist and allow the joist to be rested, by the tabs, on the top plate of a perimeter beam of a floor structure.

3. An improved steel floorjoist of claims 1 and 2, the improvement comprising a pair of extension tabs which are integral to the top chord of the joist, at distal ends of the joist, which extend past both ends of the joist and allow the joist to be rested, by the tabs, on the top plate of a perimeter beam of a floor structure.

4. An improved steel floorjoist of claims 1-3, in which the extension tabs are almost as wide as the width of the top chord of the joist.

5. A method of installing an improved steel floor joist in a building comprising:

a. Resting an improved floor joist on a perimeter beam of a floor structure, using the improvement of a pair of extension tabs which are either integral to the top chord of the joist or are added pieces of steel, attached to the top chord, at distal ends of the joist, which extend past both ends of the joist, and allow the joist to be rested, on a top plate of the perimeter beam; and b. Attaching the improved floor joist to the perimeter beam with an attachment means.

Figure 1

Figure 3 Figure 2

Figure 4

Figure 5